WASHINGTON (AFP) - A new US report Thursday painted a bleak picture of progress by Iraq's government, heaping more pressure on a weakened President George W. Bush and fueling demands in Congress to bring troops home.

Facing a maelstrom of criticism, Bush insisted America could still win the four-year war, and warned a US pull-back would mean "surrendering the future of Iraq to Al-Qaeda" and spawn chaos throughout the Middle East.

The White House's interim report into Bush's plan to surge an extra 30,000 more troops into Iraq found satisfactory progress by the Baghdad government on only eight of 18 security and political benchmarks set by Congress.

Bush said however he still had "confidence" in Iraqi Prime Minister Nuri al-Maliki and styled the report as an initial snapshot of the surge.

He vowed to make no final judgments about the plan until he had received a definitive study by US commander in Iraq General David Petraeus in September.

"I believe we can succeed in Iraq, and I know we must," Bush told a press conference called to defend his unpopular strategy and warned plummeting public opinion would not force his hand.

The report revealed efforts by Iraq to get its armed forces operating independently of US units -- a key goal of the administration's hopes to eventually cut US troop numbers -- had made "unsatisfactory progress."

Among other judgments, the report said "the prerequisites for a successful militia disarmament program are not present" in Iraq.

Baghdad had made "unsatisfactory" progress on legislation explicitly endorsed by Washington as central to efforts to quiet sectarian violence.

There was more optimism on the situation in some regions, like Anbar province, echoing recent US statements that local tribal leaders had turned sharply against members of Al-Qaeda.

Bush defended his decisions on Iraq, saying "I will be able to say, I looked in the mirror and made decisions based upon principle, not based upon politics."

"Everybody wants to be loved -- just sometimes the decisions you make and the consequences don't enable you to be loved."

But Bush's political foes went on the attack.

"It is clear that there is now a state of chaos in Iraq. And it is up to the Iraqi people to make themselves safe," said Senate Democratic Majority leader Harry Reid.

"We can't do it. It's time the training wheels come off and they take care of their own country."

His colleague, Senator Dick Durbin said: "It's sad to say, President Bush is out of touch ... with the reality of the war in Iraq."

Senator Hillary Clinton, a Democratic presidential candidate, also weighed in saying, "even the president's own portrait cannot paint over the reality on the ground: our strategy in Iraq is failing."

But Bush had a blunt message for lawmakers, hours before the House of Representatives was due to vote on a measure calling for the return of most US combat troops from Iraq by April 1.

"I don't think Congress ought to be running the war," he said in remarks likely to fuel a bitter struggle with lawmakers for control of US strategy.

One of his allies in Congress, Republican House minority leader John Boehner, accused Democrats of using US troops as "pawns in a partisan political game" and undermining Petraeus.

Bush pledged to send Secretary of State Condoleezza Rice and Secretary of Defense Robert Gates to the Middle East in August to consult US allies on the conflict.

The House bill calls for a redeployment to begin within 120 days and would force the president to report to Congress on why soldiers should stay in Iraq for limited purposes such as fighting terrorism or training Iraqi forces.

A similar bill is being debated in the Senate, but both approaches mirror earlier Democratic initiatives which Bush blocked. He signalled again Thursday he would veto any new troop withdrawal timelines.

It is not clear though if Democrats have won over enough Republicans to overcome the 60-vote hurdle in the 100-seat Senate needed to defeat Republican delaying tactics.